Bandgap reference voltage circuits are used in integrated circuits in a broad range of applications. Bandgap reference voltage circuits provide a reference voltage, typically around 1.2 volts, over a wide temperature range, e.g. between negative forty degrees Celsius and positive one hundred and twenty-five degrees Celsius. The overall accuracy of the output voltage of a bandgap reference voltage circuit may be influenced by several factors, such as process variation, device mismatch, and temperature dependency, also known as bandgap curvature or temperature-dependent curvature.
Applications in which a bandgap voltage is used as reference of precise control and regulation loops, such as direct-current-to-direct-current (DC/DC) converters, may need a voltage accuracy of 0.5% from negative forty degrees Celsius and positive one hundred and twenty-five degrees Celsius. The temperature-dependent curvature of the bandgap voltage is a significant source of error, contributing for 0.13% to the overall inaccuracy of the bandgap voltage. While the effect of process variation can be reduced by trimming or offset cancellation techniques, the bandgap reference voltage circuit may need a specific circuit to address the error introduced from the temperature-dependent curvature. However, even reducing the error due to process variation and device mismatch, achieving an overall accuracy of 0.5% across a broad range of temperatures may be difficult or uneconomical, if the error related to the bandgap curvature remains.